function change_admin(obj) {
    var user_id=$(obj).attr('value');
    $.ajax({
            url: "/admin/change_admin",
            method: "post",
            data: JSON.stringify({'user_id':user_id}),
            contentType: "application/json",
            success: function (resp) {
                if (resp.err == "0") {
                    // 刷新界面
                    alert("修改成功");
                    location.reload();
                } else {
                    alert(resp.errmsg);
                }
            }
        })
}
